Blame view
kernel/kallsyms.c
12.2 KB
1da177e4c Linux-2.6.12-rc2 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
/* * kallsyms.c: in-kernel printing of symbolic oopses and stack traces. * * Rewritten and vastly simplified by Rusty Russell for in-kernel * module loader: * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation * * ChangeLog: * * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com> * Changed the compression method from stem compression to "table lookup" * compression (see scripts/kallsyms.c for a more complete description) */ #include <linux/kallsyms.h> #include <linux/module.h> #include <linux/init.h> #include <linux/seq_file.h> #include <linux/fs.h> #include <linux/err.h> #include <linux/proc_fs.h> |
4e57b6817 [PATCH] fix missi... |
21 |
#include <linux/sched.h> /* for cond_resched */ |
1da177e4c Linux-2.6.12-rc2 |
22 |
#include <linux/mm.h> |
07354a009 [PATCH] /proc/kal... |
23 |
#include <linux/ctype.h> |
1da177e4c Linux-2.6.12-rc2 |
24 25 26 27 28 29 30 31 |
#include <asm/sections.h> #ifdef CONFIG_KALLSYMS_ALL #define all_var 1 #else #define all_var 0 #endif |
2ea038917 Revert "kbuild: s... |
32 33 34 |
/* These will be re-linked against their real values during the second link stage */ extern const unsigned long kallsyms_addresses[] __attribute__((weak)); extern const u8 kallsyms_names[] __attribute__((weak)); |
1da177e4c Linux-2.6.12-rc2 |
35 |
|
9e6c1e633 FRV: fix the exte... |
36 37 38 39 |
/* tell the compiler that the count isn't in the small data section if the arch * has one (eg: FRV) */ extern const unsigned long kallsyms_num_syms |
2ea038917 Revert "kbuild: s... |
40 |
__attribute__((weak, section(".rodata"))); |
9e6c1e633 FRV: fix the exte... |
41 |
|
2ea038917 Revert "kbuild: s... |
42 43 |
extern const u8 kallsyms_token_table[] __attribute__((weak)); extern const u16 kallsyms_token_index[] __attribute__((weak)); |
1da177e4c Linux-2.6.12-rc2 |
44 |
|
2ea038917 Revert "kbuild: s... |
45 |
extern const unsigned long kallsyms_markers[] __attribute__((weak)); |
1da177e4c Linux-2.6.12-rc2 |
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 |
static inline int is_kernel_inittext(unsigned long addr) { if (addr >= (unsigned long)_sinittext && addr <= (unsigned long)_einittext) return 1; return 0; } static inline int is_kernel_text(unsigned long addr) { if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) return 1; return in_gate_area_no_task(addr); } static inline int is_kernel(unsigned long addr) { if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) return 1; return in_gate_area_no_task(addr); } |
ffc508919 [PATCH] Create ka... |
68 69 70 71 |
static int is_ksym_addr(unsigned long addr) { if (all_var) return is_kernel(addr); |
a3b81113f remove support fo... |
72 |
return is_kernel_text(addr) || is_kernel_inittext(addr); |
ffc508919 [PATCH] Create ka... |
73 |
} |
1da177e4c Linux-2.6.12-rc2 |
74 75 76 77 78 |
/* expand a compressed symbol data into the resulting uncompressed string, given the offset to where the symbol is in the compressed stream */ static unsigned int kallsyms_expand_symbol(unsigned int off, char *result) { int len, skipped_first = 0; |
aad094701 [PATCH] move kall... |
79 |
const u8 *tptr, *data; |
1da177e4c Linux-2.6.12-rc2 |
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
/* get the compressed symbol length from the first symbol byte */ data = &kallsyms_names[off]; len = *data; data++; /* update the offset to return the offset for the next symbol on * the compressed stream */ off += len + 1; /* for every byte on the compressed symbol data, copy the table entry for that byte */ while(len) { tptr = &kallsyms_token_table[ kallsyms_token_index[*data] ]; data++; len--; while (*tptr) { if(skipped_first) { *result = *tptr; result++; } else skipped_first = 1; tptr++; } } *result = '\0'; /* return to offset to the next symbol */ return off; } /* get symbol type information. This is encoded as a single char at the * begining of the symbol name */ static char kallsyms_get_symbol_type(unsigned int off) { /* get just the first code, look it up in the token table, and return the * first char from this token */ return kallsyms_token_table[ kallsyms_token_index[ kallsyms_names[off+1] ] ]; } /* find the offset on the compressed stream given and index in the * kallsyms array */ static unsigned int get_symbol_offset(unsigned long pos) { |
aad094701 [PATCH] move kall... |
127 |
const u8 *name; |
1da177e4c Linux-2.6.12-rc2 |
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 |
int i; /* use the closest marker we have. We have markers every 256 positions, * so that should be close enough */ name = &kallsyms_names[ kallsyms_markers[pos>>8] ]; /* sequentially scan all the symbols up to the point we're searching for. * Every symbol is stored in a [<len>][<len> bytes of data] format, so we * just need to add the len to the current pointer for every symbol we * wish to skip */ for(i = 0; i < (pos&0xFF); i++) name = name + (*name) + 1; return name - kallsyms_names; } /* Lookup the address for this symbol. Returns 0 if not found. */ unsigned long kallsyms_lookup_name(const char *name) { |
9281acea6 kallsyms: make KS... |
147 |
char namebuf[KSYM_NAME_LEN]; |
1da177e4c Linux-2.6.12-rc2 |
148 149 150 151 152 153 154 155 156 157 158 |
unsigned long i; unsigned int off; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf); if (strcmp(namebuf, name) == 0) return kallsyms_addresses[i]; } return module_kallsyms_lookup_name(name); } |
1da177e4c Linux-2.6.12-rc2 |
159 |
|
75a66614d Ksplice: Add func... |
160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 |
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { char namebuf[KSYM_NAME_LEN]; unsigned long i; unsigned int off; int ret; for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf); ret = fn(data, namebuf, NULL, kallsyms_addresses[i]); if (ret != 0) return ret; } return module_kallsyms_on_each_symbol(fn, data); } EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol); |
ffc508919 [PATCH] Create ka... |
178 179 180 181 182 183 |
static unsigned long get_symbol_pos(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { unsigned long symbol_start = 0, symbol_end = 0; unsigned long i, low, high, mid; |
2ea038917 Revert "kbuild: s... |
184 185 |
/* This kernel should never had been booted. */ BUG_ON(!kallsyms_addresses); |
ffc508919 [PATCH] Create ka... |
186 187 188 189 190 |
/* do a binary search on the sorted kallsyms_addresses array */ low = 0; high = kallsyms_num_syms; while (high - low > 1) { |
2fc9c4e18 kallsyms: fix pot... |
191 |
mid = low + (high - low) / 2; |
ffc508919 [PATCH] Create ka... |
192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 |
if (kallsyms_addresses[mid] <= addr) low = mid; else high = mid; } /* * search for the first aliased symbol. Aliased * symbols are symbols with the same address */ while (low && kallsyms_addresses[low-1] == kallsyms_addresses[low]) --low; symbol_start = kallsyms_addresses[low]; /* Search for next non-aliased symbol */ for (i = low + 1; i < kallsyms_num_syms; i++) { if (kallsyms_addresses[i] > symbol_start) { symbol_end = kallsyms_addresses[i]; break; } } /* if we found no next symbol, we use the end of the section */ if (!symbol_end) { if (is_kernel_inittext(addr)) symbol_end = (unsigned long)_einittext; else if (all_var) symbol_end = (unsigned long)_end; else symbol_end = (unsigned long)_etext; } |
ffb451227 Simplify kallsyms... |
224 225 226 227 |
if (symbolsize) *symbolsize = symbol_end - symbol_start; if (offset) *offset = addr - symbol_start; |
ffc508919 [PATCH] Create ka... |
228 229 230 231 232 233 234 235 236 237 |
return low; } /* * Lookup an address but don't bother to find any names. */ int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { |
6dd06c9fb module: make modu... |
238 |
char namebuf[KSYM_NAME_LEN]; |
ffc508919 [PATCH] Create ka... |
239 240 |
if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); |
6dd06c9fb module: make modu... |
241 |
return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); |
ffc508919 [PATCH] Create ka... |
242 |
} |
1da177e4c Linux-2.6.12-rc2 |
243 244 245 246 247 248 249 250 251 252 253 254 |
/* * Lookup an address * - modname is set to NULL if it's in the kernel * - we guarantee that the returned name is valid until we reschedule even if * it resides in a module * - we also guarantee that modname will be valid until rescheduled */ const char *kallsyms_lookup(unsigned long addr, unsigned long *symbolsize, unsigned long *offset, char **modname, char *namebuf) { |
9281acea6 kallsyms: make KS... |
255 |
namebuf[KSYM_NAME_LEN - 1] = 0; |
1da177e4c Linux-2.6.12-rc2 |
256 |
namebuf[0] = 0; |
ffc508919 [PATCH] Create ka... |
257 258 |
if (is_ksym_addr(addr)) { unsigned long pos; |
1da177e4c Linux-2.6.12-rc2 |
259 |
|
ffc508919 [PATCH] Create ka... |
260 |
pos = get_symbol_pos(addr, symbolsize, offset); |
1da177e4c Linux-2.6.12-rc2 |
261 |
/* Grab name */ |
ffc508919 [PATCH] Create ka... |
262 |
kallsyms_expand_symbol(get_symbol_offset(pos), namebuf); |
7a74fc492 fix possible null... |
263 264 |
if (modname) *modname = NULL; |
1da177e4c Linux-2.6.12-rc2 |
265 266 267 268 |
return namebuf; } /* see if it's in a module */ |
6dd06c9fb module: make modu... |
269 270 |
return module_address_lookup(addr, symbolsize, offset, modname, namebuf); |
1da177e4c Linux-2.6.12-rc2 |
271 |
} |
9d65cb4a1 Fix race between ... |
272 273 274 |
int lookup_symbol_name(unsigned long addr, char *symname) { symname[0] = '\0'; |
9281acea6 kallsyms: make KS... |
275 |
symname[KSYM_NAME_LEN - 1] = '\0'; |
9d65cb4a1 Fix race between ... |
276 277 278 279 280 281 282 283 284 285 286 287 |
if (is_ksym_addr(addr)) { unsigned long pos; pos = get_symbol_pos(addr, NULL, NULL); /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), symname); return 0; } /* see if it's in a module */ return lookup_module_symbol_name(addr, symname); } |
a5c43dae7 Fix race between ... |
288 289 290 291 |
int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) { name[0] = '\0'; |
9281acea6 kallsyms: make KS... |
292 |
name[KSYM_NAME_LEN - 1] = '\0'; |
a5c43dae7 Fix race between ... |
293 294 295 296 297 298 299 300 301 302 303 304 305 |
if (is_ksym_addr(addr)) { unsigned long pos; pos = get_symbol_pos(addr, size, offset); /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), name); modname[0] = '\0'; return 0; } /* see if it's in a module */ return lookup_module_symbol_attrs(addr, size, offset, modname, name); } |
42e380832 Extend print_symb... |
306 307 |
/* Look up a kernel symbol and return it in a text buffer. */ int sprint_symbol(char *buffer, unsigned long address) |
1da177e4c Linux-2.6.12-rc2 |
308 309 310 311 |
{ char *modname; const char *name; unsigned long offset, size; |
966c8c12d sprint_symbol(): ... |
312 |
int len; |
1da177e4c Linux-2.6.12-rc2 |
313 |
|
966c8c12d sprint_symbol(): ... |
314 |
name = kallsyms_lookup(address, &size, &offset, &modname, buffer); |
1da177e4c Linux-2.6.12-rc2 |
315 |
if (!name) |
42e380832 Extend print_symb... |
316 |
return sprintf(buffer, "0x%lx", address); |
19769b762 sprint_symbol() c... |
317 |
|
966c8c12d sprint_symbol(): ... |
318 319 320 321 |
if (name != buffer) strcpy(buffer, name); len = strlen(buffer); buffer += len; |
19769b762 sprint_symbol() c... |
322 |
if (modname) |
966c8c12d sprint_symbol(): ... |
323 324 |
len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname); |
19769b762 sprint_symbol() c... |
325 |
else |
966c8c12d sprint_symbol(): ... |
326 327 328 |
len += sprintf(buffer, "+%#lx/%#lx", offset, size); return len; |
42e380832 Extend print_symb... |
329 330 331 332 333 334 335 336 |
} /* Look up a kernel symbol and print it to the kernel messages. */ void __print_symbol(const char *fmt, unsigned long address) { char buffer[KSYM_SYMBOL_LEN]; sprint_symbol(buffer, address); |
1da177e4c Linux-2.6.12-rc2 |
337 338 339 340 341 342 343 |
printk(fmt, buffer); } /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ struct kallsym_iter { loff_t pos; |
1da177e4c Linux-2.6.12-rc2 |
344 345 346 |
unsigned long value; unsigned int nameoff; /* If iterating in core kernel symbols */ char type; |
9281acea6 kallsyms: make KS... |
347 348 |
char name[KSYM_NAME_LEN]; char module_name[MODULE_NAME_LEN]; |
ea07890a6 Fix race between ... |
349 |
int exported; |
1da177e4c Linux-2.6.12-rc2 |
350 |
}; |
1da177e4c Linux-2.6.12-rc2 |
351 352 |
static int get_ksymbol_mod(struct kallsym_iter *iter) { |
ea07890a6 Fix race between ... |
353 354 355 |
if (module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value, &iter->type, iter->name, iter->module_name, &iter->exported) < 0) |
1da177e4c Linux-2.6.12-rc2 |
356 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
357 358 359 360 361 362 363 |
return 1; } /* Returns space to next name. */ static unsigned long get_ksymbol_core(struct kallsym_iter *iter) { unsigned off = iter->nameoff; |
ea07890a6 Fix race between ... |
364 |
iter->module_name[0] = '\0'; |
1da177e4c Linux-2.6.12-rc2 |
365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 |
iter->value = kallsyms_addresses[iter->pos]; iter->type = kallsyms_get_symbol_type(off); off = kallsyms_expand_symbol(off, iter->name); return off - iter->nameoff; } static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) { iter->name[0] = '\0'; iter->nameoff = get_symbol_offset(new_pos); iter->pos = new_pos; } /* Returns false if pos at or past end of file. */ static int update_iter(struct kallsym_iter *iter, loff_t pos) { /* Module symbols can be accessed randomly. */ if (pos >= kallsyms_num_syms) { iter->pos = pos; return get_ksymbol_mod(iter); } /* If we're not on the desired position, reset to new position. */ if (pos != iter->pos) reset_iter(iter, pos); iter->nameoff += get_ksymbol_core(iter); iter->pos++; return 1; } static void *s_next(struct seq_file *m, void *p, loff_t *pos) { (*pos)++; if (!update_iter(m->private, *pos)) return NULL; return p; } static void *s_start(struct seq_file *m, loff_t *pos) { if (!update_iter(m->private, *pos)) return NULL; return m->private; } static void s_stop(struct seq_file *m, void *p) { } static int s_show(struct seq_file *m, void *p) { struct kallsym_iter *iter = m->private; /* Some debugging symbols have no name. Ignore them. */ if (!iter->name[0]) return 0; |
ea07890a6 Fix race between ... |
427 428 429 430 431 432 433 |
if (iter->module_name[0]) { char type; /* Label it "global" if it is exported, * "local" if not exported. */ type = iter->exported ? toupper(iter->type) : tolower(iter->type); |
1da177e4c Linux-2.6.12-rc2 |
434 435 436 |
seq_printf(m, "%0*lx %c %s\t[%s] ", (int)(2*sizeof(void*)), |
ea07890a6 Fix race between ... |
437 438 |
iter->value, type, iter->name, iter->module_name); } else |
1da177e4c Linux-2.6.12-rc2 |
439 440 441 442 443 444 |
seq_printf(m, "%0*lx %c %s ", (int)(2*sizeof(void*)), iter->value, iter->type, iter->name); return 0; } |
15ad7cdcf [PATCH] struct se... |
445 |
static const struct seq_operations kallsyms_op = { |
1da177e4c Linux-2.6.12-rc2 |
446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 |
.start = s_start, .next = s_next, .stop = s_stop, .show = s_show }; static int kallsyms_open(struct inode *inode, struct file *file) { /* We keep iterator in m->private, since normal case is to * s_start from where we left off, so we avoid doing * using get_symbol_offset for every symbol */ struct kallsym_iter *iter; int ret; iter = kmalloc(sizeof(*iter), GFP_KERNEL); if (!iter) return -ENOMEM; reset_iter(iter, 0); ret = seq_open(file, &kallsyms_op); if (ret == 0) ((struct seq_file *)file->private_data)->private = iter; else kfree(iter); return ret; } |
15ad7cdcf [PATCH] struct se... |
472 |
static const struct file_operations kallsyms_operations = { |
1da177e4c Linux-2.6.12-rc2 |
473 474 475 |
.open = kallsyms_open, .read = seq_read, .llseek = seq_lseek, |
5a0c6a0d1 kallsyms: cleanup... |
476 |
.release = seq_release_private, |
1da177e4c Linux-2.6.12-rc2 |
477 478 479 480 |
}; static int __init kallsyms_init(void) { |
c33fff0af kernel: use non-r... |
481 |
proc_create("kallsyms", 0444, NULL, &kallsyms_operations); |
1da177e4c Linux-2.6.12-rc2 |
482 483 484 485 486 |
return 0; } __initcall(kallsyms_init); EXPORT_SYMBOL(__print_symbol); |
42e380832 Extend print_symb... |
487 |
EXPORT_SYMBOL_GPL(sprint_symbol); |